added ability to set the handle to the openssl library (so that programs that load openssl via dlopen() can still use amqp-cpp)

include/amqpcpp.h

@@ -79,4 +79,4 @@
 #include "amqpcpp/connectionhandler.h"
 #include "amqpcpp/connectionimpl.h"
 #include "amqpcpp/connection.h"
-
+#include "amqpcpp/openssl.h"

include/amqpcpp/openssl.h

@@ -0,0 +1,37 @@
+/**
+ *  OpenSSL.h
+ * 
+ *  Function to set openssl features
+ * 
+ *  @author Emiel Bruijntjes <emiel.bruijntjes@copernica.com>
+ *  @copyright 2018 Copernica BV
+ */
+
+/**
+ *  Include guard
+ */
+#pragma once
+
+/**
+ *  Begin of namespace
+ */
+namespace AMQP {
+
+/**
+ *  To make secure "amqps://" connections, AMQP-CPP relies on functions from the 
+ *  openssl library. It your application is dynamically linked to openssl (because
+ *  it was compiled with the "-lssl" flag), this works flawlessly because AMQPCPP 
+ *  can then locate the openssl symbols in its own project space. However, if the
+ *  openssl library was not linked, you either cannot use amqps:// connections,
+ *  or you have to supply a handle to the openssl library yourself, using the
+ *  following method.
+ * 
+ *  @param  handle          Handle returned by dlopen() that has access to openssl
+ */
+void openssl(void *handle);
+    
+/**
+ *  End of namespace
+ */
+}
+

src/linux_tcp/function.h

@@ -115,10 +115,11 @@ private:
 public:
     /**
      *  Constructor
+     *  @param  handle      Handle to access openssl
      *  @param  name        Name of the function
      */
-    Function(const char *name) :
+    Function(void *handle, const char *name) :
-        _method(dlsym(RTLD_DEFAULT, name)) {}
+        _method(dlsym(handle, name)) {}
 
     /**
      *  Destructor

src/linux_tcp/openssl.cpp

@@ -11,11 +11,33 @@
  */
 #include "openssl.h"
 #include "function.h"
+#include "amqpcpp/openssl.h"
 
 /**
- *  Begin of namespace
+ *  The handle to access openssl (the result of dlopen("openssl.so"))
+ *  By default we set this to RTLD_DEFAULT, so that AMQP-CPP checks the internal process space
  */
-namespace AMQP { namespace OpenSSL {
+static void *handle = RTLD_DEFAULT;
+
+/**
+ *  Just the AMQP namespace
+ */
+namespace AMQP {
+
+/**
+ *  Function to set the openssl handle
+ *  @param  ptr
+ */
+void openssl(void *ptr)
+{
+    // store handle
+    handle = ptr;
+}
+
+/**
+ *  Begin of AMQP::OpenSSL namespace
+ */
+namespace OpenSSL {
 
 /**
  *  Is the openssl library loaded?
@@ -24,7 +46,7 @@ namespace AMQP { namespace OpenSSL {
 bool valid()
 {
     // create a function
-    static Function<decltype(::SSL_CTX_new)> func("SSL_CTX_new");
+    static Function<decltype(::SSL_CTX_new)> func(handle, "SSL_CTX_new");
 
     // we need a library
     return func;
@@ -37,13 +59,13 @@ bool valid()
 const SSL_METHOD *TLS_client_method()
 {
     // create a function that loads the method
-    static Function<decltype(TLS_client_method)> func("TLS_client_method");
+    static Function<decltype(TLS_client_method)> func(handle, "TLS_client_method");
     
     // call the openssl function
     if (func) return func();
     
     // older openssl libraries do not have this function, so we try to load an other function
-    static Function<decltype(TLS_client_method)> old("SSLv23_client_method");
+    static Function<decltype(TLS_client_method)> old(handle, "SSLv23_client_method");
     
     // call the old one
     return old();
@@ -57,7 +79,7 @@ const SSL_METHOD *TLS_client_method()
 SSL_CTX *SSL_CTX_new(const SSL_METHOD *method) 
 {
     // create a function
-    static Function<decltype(::SSL_CTX_new)> func("SSL_CTX_new");
+    static Function<decltype(::SSL_CTX_new)> func(handle, "SSL_CTX_new");
     
     // call the openssl function
     return func(method);
@@ -73,7 +95,7 @@ SSL_CTX *SSL_CTX_new(const SSL_METHOD *method)
 int SSL_read(SSL *ssl, void *buf, int num)
 {
     // create a function
-    static Function<decltype(::SSL_read)> func("SSL_read");
+    static Function<decltype(::SSL_read)> func(handle, "SSL_read");
     
     // call the openssl function
     return func(ssl, buf, num);
@@ -89,7 +111,7 @@ int SSL_read(SSL *ssl, void *buf, int num)
 int SSL_write(SSL *ssl, const void *buf, int num)
 {
     // create a function
-    static Function<decltype(::SSL_write)> func("SSL_write");
+    static Function<decltype(::SSL_write)> func(handle, "SSL_write");
     
     // call the openssl function
     return func(ssl, buf, num);
@@ -104,7 +126,7 @@ int SSL_write(SSL *ssl, const void *buf, int num)
 int SSL_set_fd(SSL *ssl, int fd) 
 {
     // create a function
-    static Function<decltype(::SSL_set_fd)> func("SSL_set_fd");
+    static Function<decltype(::SSL_set_fd)> func(handle, "SSL_set_fd");
     
     // call the openssl function
     return func(ssl, fd);
@@ -119,7 +141,7 @@ int SSL_set_fd(SSL *ssl, int fd)
 int SSL_pending(const SSL *ssl)
 {
     // create a function
-    static Function<decltype(::SSL_pending)> func("SSL_pending");
+    static Function<decltype(::SSL_pending)> func(handle, "SSL_pending");
     
     // call the openssl function
     return func(ssl);
@@ -132,7 +154,7 @@ int SSL_pending(const SSL *ssl)
 void SSL_CTX_free(SSL_CTX *ctx)
 {
     // create a function
-    static Function<decltype(::SSL_CTX_free)> func("SSL_CTX_free");
+    static Function<decltype(::SSL_CTX_free)> func(handle, "SSL_CTX_free");
     
     // call the openssl function
     return func(ctx);
@@ -146,7 +168,7 @@ void SSL_CTX_free(SSL_CTX *ctx)
 void SSL_free(SSL *ssl)
 {
     // create a function
-    static Function<decltype(::SSL_free)> func("SSL_free");
+    static Function<decltype(::SSL_free)> func(handle, "SSL_free");
     
     // call the openssl function
     return func(ssl);
@@ -160,7 +182,7 @@ void SSL_free(SSL *ssl)
 SSL *SSL_new(SSL_CTX *ctx)
 {
     // create a function
-    static Function<decltype(::SSL_new)> func("SSL_new");
+    static Function<decltype(::SSL_new)> func(handle, "SSL_new");
     
     // call the openssl function
     return func(ctx);
@@ -174,7 +196,7 @@ SSL *SSL_new(SSL_CTX *ctx)
 int SSL_up_ref(SSL *ssl)
 {
     // create a function
-    static Function<decltype(SSL_up_ref)> func("SSL_up_ref");
+    static Function<decltype(SSL_up_ref)> func(handle, "SSL_up_ref");
     
     // call the openssl function if it exists
     if (func) return func(ssl);
@@ -192,7 +214,7 @@ int SSL_up_ref(SSL *ssl)
 int SSL_shutdown(SSL *ssl)
 {
     // create a function
-    static Function<decltype(::SSL_shutdown)> func("SSL_shutdown");
+    static Function<decltype(::SSL_shutdown)> func(handle, "SSL_shutdown");
     
     // call the openssl function
     return func(ssl);
@@ -205,7 +227,7 @@ int SSL_shutdown(SSL *ssl)
 void SSL_set_connect_state(SSL *ssl)
 {
     // create a function
-    static Function<decltype(::SSL_set_connect_state)> func("SSL_set_connect_state");
+    static Function<decltype(::SSL_set_connect_state)> func(handle, "SSL_set_connect_state");
     
     // call the openssl function
     func(ssl);
@@ -220,7 +242,7 @@ void SSL_set_connect_state(SSL *ssl)
 int SSL_do_handshake(SSL *ssl)
 {
     // create a function
-    static Function<decltype(::SSL_do_handshake)> func("SSL_do_handshake");
+    static Function<decltype(::SSL_do_handshake)> func(handle, "SSL_do_handshake");
     
     // call the openssl function
     return func(ssl);
@@ -234,7 +256,7 @@ int SSL_do_handshake(SSL *ssl)
 int SSL_get_shutdown(const SSL *ssl)
 {
     // create a function
-    static Function<decltype(::SSL_get_shutdown)> func("SSL_get_shutdown");
+    static Function<decltype(::SSL_get_shutdown)> func(handle, "SSL_get_shutdown");
     
     // call the openssl function
     return func(ssl);
@@ -249,7 +271,7 @@ int SSL_get_shutdown(const SSL *ssl)
 int SSL_get_error(const SSL *ssl, int ret)
 {
     // create a function
-    static Function<decltype(::SSL_get_error)> func("SSL_get_error");
+    static Function<decltype(::SSL_get_error)> func(handle, "SSL_get_error");
     
     // call the openssl function
     return func(ssl, ret);
@@ -266,7 +288,7 @@ int SSL_get_error(const SSL *ssl, int ret)
 long SSL_ctrl(SSL *ssl, int cmd, long larg, void *parg)
 {
     // create a function
-    static Function<decltype(::SSL_ctrl)> func("SSL_ctrl");
+    static Function<decltype(::SSL_ctrl)> func(handle, "SSL_ctrl");
     
     // call the openssl function
     return func(ssl, cmd, larg, parg);
@@ -282,7 +304,7 @@ long SSL_ctrl(SSL *ssl, int cmd, long larg, void *parg)
 int SSL_use_certificate_file(SSL *ssl, const char *file, int type)
 {
     // create a function
-    static Function<decltype(::SSL_use_certificate_file)> func("SSL_use_certificate_file");
+    static Function<decltype(::SSL_use_certificate_file)> func(handle, "SSL_use_certificate_file");
     
     // call the openssl function
     return func(ssl, file, type);